A psu to power an egpu is always needed. The bottom panel comes off easy enough to access the mpcie where the wireless card is but it's your only slot that you can use for an egpu. Mpcie adapters are cheap, $30 or so but you will be limited to pcie x1 which causes a severe bottleneck. Since the 960m is decent, similar to a 750ti, you'd have to go pretty high to make up for that bottleneck, like a 1060 6gb for a worthwhile increase.